Mechanism for tensioning a compensation spring for a closing or sun protection installation

ABSTRACT

The invention relates to a mechanism comprising at least one spring ( 3 ) for compensating the weight of a closing screen, said spring ( 3 ) being fixed, at one of its ends ( 32 ), to a ring ( 6 ) which is rotatably arranged around a shaft ( 4 ) having a circular cross-section. A stop spring ( 7 ) which is arranged around the shaft ( 4 ) ensures a one-way coupling between the ring ( 6 ) and the shaft ( 4 ), means ( 8 ) being provided for controlling the centripetal effort exerted on said shaft ( 4 ) by the stop spring ( 7 ).

The invention relates to a mechanism for manoeuvring a closing or sunprotection installation. The invention also relates to a closing or sunprotection installation incorporating such a mechanism.

Closing installation is understood to mean doors, portals, blinds,shutters and equivalent equipment.

In a closing or sun protection installation, a screen, which may be asupple shade body or a rigid or semi-rigid panel, is displaced oppositean opening in order to close the latter selectively. The weight of thisscreen exerts on the drive means a torque which is variable,particularly as a function of the position of this screen. It is knownto use so-called “compensating” springs to compensate this torque atleast partially.

For an installation to function correctly, it is necessary that theeffort of compensation exerted by the spring be adapted to the torquedeveloped by the screen which influences the drive means. This torque isa function of the dimensions of the screen, of its specific weight andof its position with respect to the opening. It is therefore known toprovide means for adjusting a compensating spring, particularly when itis initially loaded. U.S. Pat. No. 4,817,927 teaches mounting one end ofa compensating spring on a ring capable of rotating about a fixed pin ofthe installation and immobilizing this ring in rotation with respect tothis pin thanks to a screw which, when the tension of the spring isadjusted, must be untightened. This obliges the operator to exert,during such adjustment, a torque on the ring in order to avoid anaccidental and sudden unloading of the spring. It is therefore necessaryfor the operator to manipulate, in one hand, a tool for exerting atorque on the ring and, in the other hand, the locking screw, thisinvolving a particular technical gesture which is not necessarilyaccessible to a person of little experience.

It is also known, for example from U.S. Pat. No. 4,981,165, to use awheel and endless screw system for adjusting the position of a ring onwhich the end of a compensating spring is immobilized. Such a device isrelatively complex and expensive.

It is a more particular object of the invention to overcome thesedrawbacks by proposing a manoeuvring mechanism in which the tension of acompensating spring may be adjusted easily and in safety, by means of asimple and reliable device.

In this spirit, the invention relates to a mechanism for manoeuvring aclosing or sun protection installation, this mechanism being mounted inor on a fixed structure and comprising a screen for closing an openingmade in this structure, while it also comprises at least one spring forcompensating the weight of this screen, this spring being kinematicallyconnected, by one of its ends, with the afore-mentioned fixed structureand, by its other end, with the afore-mentioned screen. This mechanismis characterized in that it comprises a one-way coupling deviceincluding a stop spring disposed between the compensating spring and thefixed structure or between the compensating spring and the screen, whilemeans fast with the compensating spring are arranged to exert on thestop spring an effort of blocking the latter with respect to the fixedstructure or to the screen.

Thanks to the use of a stop spring, an automatic blocking in rotation isobtained of the end of the compensating spring connected to the couplingwith respect to the fixed structure or to the screen. This blocking isobtained as long as there is no application of a voluntary effort ofadjustment aiming at modifying the angular position of this end, i.e. atmodifying the tension of the compensating spring. The blocking effort isagain exerted as soon as the effort of adjustment ceases, unlike theknown devices, for example, from U.S. Pat. No. 4,817,927. The inventiontherefore proceeds with an original and particularly advantageous use ofa lock spring whose functioning is, furthermore, known, for example fromFR-A-1 425 353 for other applications.

According to advantageous but non-obligatory aspects of the invention,the mechanism incorporates one or more of the following characteristics:

-   -   The means for exerting the blocking effort comprise a ring        disposed, with possibility of rotation, around or partially        inside an element of circular cross-section. The ring may be        provided with a housing for receiving the two curved ends of the        stop spring. This housing is advantageously provided with two        surfaces adapted to exert on these ends an effort of relative        approach.    -   Means are provided for adjusting the intensity of the blocking        effort. These means make it possible to reduce or to eliminate        the effort exerted by the stop spring and thus to release one of        the ends of the compensating spring in order to allow adjustment        of its tension. These adjusting means advantageously comprise a        ring mounted, with possibility of rotation, around an element of        circular cross-section and provided with a projection adapted to        be interposed between the curved ends of the stop spring.        In addition, this ring may be provided to present catches or        notches for interaction with a tool for controlling its angular        position around the circular element. In this way, the tool        makes it possible to exert on the ring an effort of rotation        about the element of circular cross-section, this effort being        transmitted by the projection to one or the other of the curved        ends of the stop spring, this having the effect of expanding the        latter by releasing the ring fast with the compensating spring        which may in that case rotate in the desired direction. In a        variant, the afore-mentioned adjusting means may comprise a        shaft provided with a radial projection adapted to be interposed        between the curved ends of the stop spring.    -   According to a first form of embodiment, the circular element is        a fixed central shaft extending over substantially the whole        width of the opening to be closed.    -   According to another embodiment, the circular element is a        casing of a device for driving in rotation a member winding the        closing screen or an associated effort transmission element.    -   The blocking effort is centripetal and exerted on the element of        circular cross-section.    -   According to a variant embodiment of the invention, the element        of circular cross-section surrounds the stop spring and a part        of the ring exerting the blocking effort, this effort being        centrifugal and exerted on the element of circular        cross-section.    -   The spring, the ring, the circular element and the control means        may be at least partially housed inside a shaft for winding the        closing screen or an associated effort transmission element. In        that case, this winding shaft is advantageously provided with at        least one opening giving access to the control means,        particularly by an appropriate tool.

The invention finally relates to a closure/sun protection installationwhich comprises a mechanism as described previously. Such aninstallation is reliable and economical, while it offers the possibilityof an easy adjustment of the tension of a compensating spring that itincludes, without danger, on its site of use.

The invention will be more readily understood and other advantagesthereof will appear more clearly in the light of the followingdescription of seven forms of embodiment of a closing installationaccording to the invention, given solely by way of example and made withreference to the accompanying drawings, in which:

FIG. 1 is a partial longitudinal section of an installation inaccordance with a first form of embodiment of the invention.

FIG. 2 is an exploded view in perspective of the elements shown indetail II in FIG. 1.

FIG. 3 is a view in perspective of the elements shown in FIG. 2 seenfrom another angle.

FIG. 4 is a view in the direction of arrow IV in FIG. 1, while thetension of a compensating spring is being adjusted.

FIG. 5 is a longitudinal section of an installation in accordance with asecond form of embodiment of the invention.

FIG. 6 is a view similar to FIG. 1 for an installation in accordancewith a third form of embodiment of the invention.

FIG. 7 is a view in perspective of a part of the installation of FIG. 6,while the tension of a compensating spring is being adjusted.

FIG. 8 is a view similar to FIG. 6 for an installation in accordancewith a fourth form of embodiment of the invention.

FIG. 9 is a view similar to FIG. 6 for a mechanism in accordance with afifth form of embodiment of the invention.

FIG. 10 is a section along line X-X in FIG. 9.

FIG. 11 is a view similar to FIG. 6 for a mechanism in accordance with asixth form of embodiment of the invention.

FIG. 12 is a section along line XII-XII in FIG. 11.

FIG. 13 is a partial longitudinal section of a mechanism in accordancewith a seventh form of embodiment of the invention, and

FIG. 14 is a section along line XIV-XIV in FIG. 13.

The installation shown in FIGS. 1 to 4 comprises a screen body Tintended to be selectively wound around a substantially horizontalgeometrical axis X-X′ fixed with respect to the masonry M of a buildingin which is made an opening O to be closed with the screen body T. Thescreen body T is connected by a plurality of straps, of which only oneis visible in FIG. 1 with reference 1, to winding discs of which onlyone is visible in FIG. 1 with reference 2. Two compensating springs 3and 3′ are mounted to exert on the disc 2 an effort opposite the torqueresulting from the weight of the screen body T with respect to the axisX-X′. The discs 2 and equivalent are mounted to rotate freely around ashaft 4 of circular cross-section which is fixed, thanks to brackets 41,with respect to the masonry M.

Means for driving the screen body T in rotation about axis X-X′ may beprovided, such drive means being able to be mechanical or electrical. Asa variant, the screen body T is controlled by a direct action of theuser on the lower slat thereof.

The springs 3 and 3′ are each immobilized on the truncated surface 51 or51′ of two rings 5 and 5′ rendered fast by keys 52, the ring 5′ being inmesh with the disc 2. In practice, a first end 31 or 31′ of a spring 3or 3′ is wound on a surface 51 or 51′, a hook possibly being formed inorder to anchor these ends firmly with respect to the rings 5 and 5′.

At the level of their respective opposite ends 32 and 32′, the springs 3and 3′ are immobilized on rings 6 and 6′ which each comprise a truncatedsurface 62 and 62′ for receiving the ends 32 and 32′.

As is visible in FIGS. 2 and 3, the ring 6 is provided with a centralopening 61 of circular shape, whose diameter allows it to rotate aboutthe shaft 4. The surface 62 is stepped in order to facilitatepositioning of the end 32 of the spring 3. The ring 6 also comprises asleeve 63 in which is formed a notch 64 of which 641 and 642 denote thelateral edges and 643 the bottom edge.

A spring 7 is disposed around the shaft 4 and inside the sleeve 63. 71and 72 denote the ends of the spring 7 which is a stop spring in that itis adapted to brake the ring 6 with respect to the shaft 4, i.e., inpractice, to immobilize the ring 6 in rotation about axis X-X′ thanks toa centripetal effort E.

A second ring 8 is also mounted around the shaft 4, with possibility ofrotation, this ring being provided with a projection 81 which extends,with respect to a side 82 of the ring 8, in a direction substantiallyparallel to axis X-X′. The projection 81 has a width allowing it to beinserted between the ends 71 and 72 of the stop spring 7, while thenotch 64 has a width allowing it to receive the ends 71 and 72 betweenthe edges 641 and 642.

The ring 8 is also provided with a plurality of peripheral grooves 83which make it possible easily to exert on the ring 8 a torque withrespect to axis X-X′.

Functioning is as follows:

By default, and in the absence of action on the ring 8, when a torque C₁is exerted on the ring 6 by the spring 3 due to its loading, this torqueC₁ has the effect of displacing the edge 641 of the notch 64 up tocontact with the end 71 of the spring 7, the edge 641 in that caseexerting on the end 71 an effort F₁ directed towards the edge 642, thishaving the effect of tightening the spring 7 on the shaft 4, increasingthe intensity of the centripetal effort E of blocking of the spring 7 onthe shaft 4. The movement of the ring 6 is thus limited by itsinteraction with the end 71.

If a torque C₂ directed in opposite direction with respect to torque C₁is exerted by the spring 3 on the ring 6, this torque is translated by adisplacement of the edge 642 up to contact with the end 72 of the spring7 and, as previously, by a tightening of this spring on the shaft 4 andby an increase in the centripetal effort of blocking E.

In this way, the stop spring 7 makes it possible to immobilize the ring6 on the shaft 4, despite the torques C₁ or C₂ transmitted by the spring3.

However, it is possible to rotate the ring 6 about axis X-X′ in order toadjust the tension of the spring 3. In effect, when a torque C₃ isexerted on the ring 8 towards the right in FIG. 3, this has the effectof bringing an edge 811 of the projection 81 up to contact with the end71 of the spring 7, then of exerting on this end an effort F′₁ oppositethe effort F₁ previously mentioned, this effort F′₁ having the effect ofradially expanding the spring 7 which then releases its centripetaleffort E on the shaft 4. It is thus possible to rotate, in the directionof torque C₃, both the ring 8, the spring 7 and the ring 6, this havingthe effect of modifying the tension of the spring 3.

An adjustment in opposite direction may be obtained by exerting a torqueC₄, directed in the direction opposite to torque C₃. The effort C₄induces a displacement of the opposite edge 812 of the projection 81 upto contact with the end 72, then a displacement of this end in thedirection of edge 641, this having the effect of expanding the spring 7and thus of allowing the drive of the ring 6 in the direction of thetorque C₄.

As shown in FIG. 4, a spanner 9 may be used for exerting the torque C₃thanks to an effort F₃ exerted on its handle 91. The spanner 9 isprovided with a nose 92 adapted to penetrate in one of the grooves 83.When the torque C₄ must be applied, the spanner 9 is returned and aneffort in direction opposite the effort F₃ is exerted on the handle 91.

According to a variant of the invention (not shown), the structure shownin FIGS. 1 to 4 may be modified so that the rings 5 and 5′ are fixed ona bracket mounted on the fixed structure of the building, the shaft 4 inthat case being rotating and bearing at its ends pulleys on which iswound a hoisting cable connected to the screen body T. For the rest,functioning is the same as that mentioned hereinabove.

In the second form of embodiment of the invention shown in FIG. 5,elements similar to those of the first embodiment bear identicalreferences increased by 100. In this installation, a fixed shaft 104 isimmobilized with respect to the masonry M of a building thanks tobrackets 141 and 141′. X-X′ denotes the longitudinal axis of the shaft104. Two discs 102 and 102′ are mobile in rotation about the shaft 104and axis X-X′ and allow the controlled winding of a screen body Tintended to close an opening O.

Two compensating springs 103 and 103′ each have a first end 131 or 131′fast with a disc 102 or 102′ and a second end 132 or 132′ fast with aring 106 or 106′ mounted, with possibility of rotation, on shaft 104. Aspreviously, the ring 106 forms a sleeve 163 inside which is disposed astop spring 107 of which the ends 171 and 172 are provided to interactwith a projection 181 in one piece with a ring 108 mounted, withpossibility of rotation, about the shaft 104. The centripetal effort Eexerted by the spring 107 on the shaft 104 may, as previously, becontrolled thanks to the ring 108.

An equivalent structure is provided at the level of the ring 106′ whichis associated with a stop spring 107′ and with a control ring 108′.

In the third form of embodiment of the invention shown in FIGS. 6 and 7,elements similar to those of the first embodiment bear identicalreferences increased by 200. In this embodiment, the screen body T of aninstallation may be selectively wound around a horizontal axis X-X′which is a central axis of a fixed, circular shaft 204, this shaft beingsupported by a bracket 241 fixed on the masonry M of a building.

A spacer disc 202 supports a hollow tube 245 around the shaft 204. Anequivalent disc is provided on the opposite side of the installation,this making it possible to maintain the tube 245 in a position centredon the axis X-X′, with possibility of rotation, for the selectivewinding of the screen body T.

A compensating spring 203 is more or less tightened between a truncatedsurface 221 of the disc 202 and a truncated surface 261 of a ring 206similar to rings 6 and 106 of the first and second embodiments. A stopspring 207 and a control ring 208 are associated with the ring 206, thismaking it possible to control the centripetal effort E exerted by thespring 207 on the shaft 204. The ring 208 is provided with notches 283in which a manoeuvring member such as the end 292 of a screwdriver 209may be introduced. To that end, the tube 245 is provided with an orifice245 a in which the tip 292 can be introduced. It is thus possible toexert on the handle 291 of the screwdriver 209 an effort F₄ or F′₄ suchthat the shank 293 of the screwdriver 209 pivots about its point ofabutment on the edge of the orifice 245 a, with the result that acorresponding effort F₅ or F′₅ is exerted in one of the notches 283.This has the effect of rotating the ring 208 and, as previously, ofexpanding the spring 207, of driving the ring 206 and of loading thespring 203 more or less.

In the fourth form of embodiment of the invention shown in FIG. 8,elements similar to those of the first embodiment bear identicalreferences increased by 300. In this embodiment, an electric gear-motor343 is housed in a casing 304 of circular cross-section which is fixedwith respect to the masonry M of a building thanks to a bracket 341. Theoutput shaft 344 of the gear-motor 343 is inserted in a central opening322 of a disc 323 for driving in rotation a hollow tube 345 formingshaft for winding the screen body T of the installation, about ageometrical axis X-X′ which is the central axis of the casing 304.

A circular distance piece 302 is fast in rotation with the tube 345 andmounted, with possibility of rotation, about the casing 304.

A compensating spring 303 is disposed around the casing 303, inside thetube 345. This spring 303 is fixed by one of its ends 331 on thedistance piece 302 and by its other end 332 on a ring 306 similar to therings 6, 106 and 206 of the preceding embodiments. A stop spring 307 isdisposed around the casing 304 inside a sleeve 363 formed by the ring306. The curved ends 371 and 372 of the spring 307 are capable ofinteracting with a projection 381 of a control ring 308 mounted, withpossibility of rotation, about the casing 304. It is thus possible toinfluence the intensity of the centripetal effort E exerted by thespring 307 on the casing 304.

The tube 345 is provided with a plurality of orifices 345 a making itpossible to access grooves 383 made on the outer radial surface of thering 308, this in order to control the angular position of the ring 308about axis X-X′ and to drive, after radial expansion of the spring 307,the ring 306 in rotation about axis X-X′ in order to load the spring 303more or less.

In the fifth form of embodiment of the invention shown in FIGS. 9 and10, elements similar to those of the first embodiment bear identicalreferences increased by 400. In this embodiment, the screen body T of aninstallation may be selectively wound around a horizontal axis X-X′which is a central geometrical axis of a hollow tube 445. The hollowtube is fast in rotation with a ring 405 mounted to pivot, about axisX-X′ on a support 442 fixed on a bracket 441 immobilized with respect tothe masonry M of the building.

A shaft 408 extends substantially along axis X-X′, passing through theelements 441 and 442 and is equipped, at the level of a first end 408 a,with a drive block adapted to cooperate with a spanner, a crank or anyother means for controlling the rotation of the shaft 408.

At the level of its end 408 b opposite the end 408 a, the shaft 408 issurrounded by a ring 406 that may rotate, with a limited angularclearance, about the end 408 b. A snap ring 492 makes it possible toimmobilize the ring 406 axially on the shaft 408. The shaft 408 isprovided with a radial projection 481, while the ring 406 forms a sleeve463 which partially surrounds the shaft 408, with the exception of theprojection 481. The elements 463 and 481 are arranged inside a dish 443extending a hollow shaft 404 fast with the support 442.

A stop spring 407 is disposed between the elements 463 and 481, on theone hand, and the dish 443, on the other hand. 471 and 472 respectivelydenote the ends of the spring 407.

A compensating spring 403 is disposed between the rings 405 and 406,being fast in rotation with each of them.

As a function of the torque transmitted by the spring 403, the ring 406exerts on one of the ends 471 or 472 an effort which is translated by acentrifugal expansion of the spring 407, such expansion inducing acentrifugal effort E for blocking the spring 407 with respect to thedish 443, i.e. through it and through the shaft 404 with respect to thesupport 442 and the masonry M of the building.

When the tension of the spring 403 is to be adjusted, it suffices torotate with the crank 491 the shaft 408 of which the projection 481exerts on one of the ends 471 or 472 an effort such that the spring iscompressed, to such a point that it is possible to rotate the elements406 to 408 inside the dish 443.

In the sixth form of embodiment of the invention shown in FIGS. 11 and12, elements similar to those of the first embodiment bear identicalreferences increased by 500. In this embodiment, the screen body T of aclosing installation may be selectively wound about a horizontal axisX-X′ on which is centred a hollow tube 545 for winding a screen body T.

As previously, a bracket 541 is fixed with respect to the masonry M of abuilding, this bracket supporting a casing 504 enclosing the sameelements are the casing 304 of the fourth embodiment. An output shaft544 of the casing 504 is fast with a disc 523 for driving the tube 545in rotation. A ring 505 is fixed in rotation around the end of thecasing 504 most remote from the bracket 541, while a second ring 506 ismounted about the end of this casing closest to the bracket withpossibility of rotation.

A compensating spring 503 is tightened between the rings 505 and 506,while a third ring 508 is mounted, with possibility of rotation, aboutthe casing 504, in the vicinity of the ring 506. The ring 508 isprovided with a projection 581 adapted to be engaged in a notch 564formed by the ring 506. A ring 504′ fast with the tube 545 is alsomounted, with possibility of rotation and in the vicinity of the ring506, around the casing 504, this ring 504′ forming a sleeve 547 whichsurrounds at least partially the rings 508 and 506, as well as a stopspring 507 whose ends 571 and 572 are engaged in the notch 564, oneither side of the end 581. The functioning is similar to that envisagedpreviously, the ring 508, accessible through one or more openings 545 amade in the ring 504′, being provided with peripheral elements in relief583 such as grooves making it possible to control the intensity of thecentrifugal blocking effort E exerted by the spring 507 on the ring 504′fast with the tube 545.

It should be noted that this form of embodiment differs from thepreceding ones insofar as the one-way coupling, which comprises a stopspring, is integrated between the compensating spring 503 and the screenbody T and not between this spring and the masonry M, as in thepreceding cases.

The seventh form of embodiment of the invention shown in FIGS. 13 and 14concerns an application of the invention to the case of a spring box 633being used for containing a spring 603 for compensating the weight of ascreen body T intended to be wound around a horizontal axis X-X′ alsoforming axis of symmetry of a tube 604 supported by a bracket 641immobilized with respect to the masonry M of a building. One end 631 ofthe spring 603 is fast with the casing 633 a of the box 633 whichrotates about axis X-X′ when the screen body T is being wound orunwound. Furthermore, the second end 632 of the spring 603 is fast witha ring 606 mounted to pivot about the shaft 604 and which extends by asleeve 663 also surrounding the shaft 604 and inside which is disposed astop spring 607 of which the curved ends 671 and 672 extend in a notch664 made in the sleeve 663. A ring 608 provided with a projection 681engaged in the notch 664 makes it possible, as previously, to controlthe intensity of a

centripetal effort E directed towards axis X-X′ and exerted by the stopspring 607.

The characteristics of the different forms of embodiment described maybe combined together without departing from the scope of the presentinvention. Similarly, obvious modifications may be made to the forms ofembodiment described.

1. Mechanism for manoeuvring a closing or sun protection installation,said mechanism being mounted in or on a fixed structure and comprising ascreen for closing an opening made in said structure and at least onespring for compensating the weight of said screen, said spring being, innormal functioning of the installation, kinematically connected, by oneof its ends, with said structure and, by its other end, with saidscreen, characterized in that it comprises a one-way coupling deviceincluding a stop spring (7; 107; 207; 307; 407; 507; 607) disposedbetween said compensating spring (3; 103; 203; 303; 403; 503; 603) andsaid fixed structure (M) or between said compensating spring and saidscreen (T), means (6; 106; 207; 306; 406; 506; 606) fast with saidcompensating spring being arranged to exert on said stop spring aneffort (E) of blocking said stop spring with respect to said fixedstructure or to said screen.
 2. Mechanism according to claim 1,characterized in that said first means comprise a ring (6; 106; 206;306; 406; 506; 606) disposed, with possibility of rotation, about orpartially inside an element (4; 104; 204; 304; 404; 504; 604) ofcircular cross-section.
 3. Mechanism according to claim 2, characterizedin that said ring (6; 106; 206; 306; 406; 506; 606) is provided with ahousing (64) for receiving the two curved ends (71, 72; 171, 172; 371,372; 471; 472; 571; 572; 671; 672) of said stop spring (7; 107; 207;307; 407; 507; 607).
 4. Mechanism according to claim 3, characterized inthat said housing (64) is provided with two surfaces (641, 642) adaptedto exert on said ends (71, 72) an effort (F₁) of relative approach. 5.Mechanism according to claim 1, characterized in that it comprises means(8; 108; 208; 308; 408; 508; 608) for adjusting the intensity of saidblocking effort (E).
 6. Mechanism according to claim 5, characterized inthat the adjusting means comprise a ring (8; 108; 208; 308; 508; 608)mounted, with possibility of rotation, about an element (4; 104; 204;304; 504; 604) of circular cross-section provided with a projection (81;181; 381; 581; 681) adapted to be interposed between the curved ends(71, 72; 171, 172; 371, 372; 571; 572; 671; 672) of said stop spring (7;107; 207; 307; 507; 607).
 7. Mechanism according to claim 6,characterized in that said ring (8; 108; 208; 308; 508; 608) is providedwith catches or notches (83; 283; 383; 583) for interaction with a tool(9; 209) for controlling the angular position of said ring around saidelement (4; 104; 204; 304; 504; 604).
 8. Mechanism according to claim 5,characterized in that said adjusting means comprise a shaft (408)provided with a radial projection (481) adapted to be interposed betweenthe curved ends (471, 472) of said stop spring (407).
 9. Mechanismaccording to claim 2, characterized in that said element of circularcross-section is a fixed central shaft (4; 104; 204; 604) extending oversubstantially the width of the opening (O) to be closed by said screen(T).
 10. Mechanism according to claim 2, characterized in that saidcircular element is a casing (304; 504) of a device (343) for driving inrotation a member (345; 545) for winding said closing screen (T) or anassociated effort transmission element (1).
 11. Mechanism according toclaim 2, characterized in that said blocking effort (E) is centripetaland exerted on said element (4; 104; 204; 304; 504; 604) of circularcross-section.
 12. Mechanism according to claim 2, characterized in thatsaid element (404) of circular cross-section surrounds said stop spring(407) and a part of said ring (406), said blocking effort (E) beingcentrifugal and exerted on said element of circular cross-section. 13.Mechanisms according to claim 2, characterized in that said stop spring(207; 307; 407; 507), said ring (206; 306; 406; 506), said element ofcircular cross-section (204; 304; 404; 504) and said control means (208;308; 408; 508) are at least partially housed inside a shaft (245; 345;445; 545) for winding said closing screen (T) or an associated efforttransmission element (1).
 14. Mechanism according to claim 13,characterized in that said shaft (245; 345; 445; 545) is provided withat least one opening (245 a, 345 a, 545 a) for access to said controlmeans, particularly by an appropriate tool (209).
 15. Closing or sunprotection installation, characterized in that it comprises a mechanism(1-92; 102-181; 202-293; 302-383; 403-492; 503-583; 603-681) accordingto claim 1.